#!/bin/sh
#
# Susan interface to mtx autoloader
#
#  If you set in your Device resource
#
#  Changer Command = "path-to-this-script/mtx-changer %c %o %S %a %d"
#    you will have the following input to this script:
#
#  So Susan will always call with all the following arguments, even though
#    in come cases, not all are used.
#
#  mtx-changer "changer-device" "command" "slot" "archive-device" "drive-index"
#		   $1		   $2	    $3	      $4	       $5
#
#  for example:
#
#  mtx-changer /dev/sg0 load 1 /dev/nst0 0 (on a Linux system)
#
#  will request to load the first cartidge into drive 0, where
#   the SCSI control channel is /dev/sg0, and the read/write device
#   is /dev/nst0.
#
#  The commands are:
#      Command		  Function
#      unload		  unload a given slot
#      load		  load a given slot
#      loaded		  which slot is loaded?
#      list		  list Volume names (requires barcode reader)
#      slots		  how many slots total?
#      listall		  list all info
#      transfer
#
#  Slots are numbered from 1 ...
#  Drives are numbered from 0 ...
#
#
#  If you need to an offline, refer to the drive as $4
#    e.g.   mt -f $4 offline
#
#  Many changers need an offline after the unload. Also many
#   changers need a sleep 60 after the mtx load.
#
#  N.B. If you change the script, take care to return either
#   the mtx exit code or a 0. If the script exits with a non-zero
#   exit code, Susan will assume the request failed.
#

# source our conf file
if test ! -r @confdir@/mtx-changer.conf ; then
  echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
  echo "ERROR: @confdir@/mtx-changer.conf file not found!!!!"
  echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
  exit 1
fi
. @confdir@/mtx-changer.conf

MTX=@MTX@
if test ! -x "$MTX" ; then
  echo "ERROR: mtx program not found ($MTX)"
  exit 1
fi

dbgfile="@logdir@/mtx.log"
if test ${debug_log} -ne 0 ; then
  touch $dbgfile
fi
debug() {
    if test -f $dbgfile; then
        echo "`date +\"%Y%m%d-%H:%M:%S\"` $*" >> $dbgfile
    fi
}


#
# Create a temporary file
#
make_temp_file() {
  TMPFILE=`mktemp @working_dir@/mtx.XXXXXXXXXX`
  if test x${TMPFILE} = x; then
     TMPFILE="@working_dir@/mtx.$$"
     if test -f ${TMPFILE}; then
	echo "ERROR: Temp file security problem on: ${TMPFILE}"
	exit 1
     fi
  fi
}

#
#  Create a temporary file for stderr
#
#  Note, this file is used because sometime mtx emits
#  unexpected error messages followed by the output
#  expected during success.
#  So we separate STDOUT and STDERR in
#  certain of the mtx commands. The contents of STDERR
#  is then printed after the STDOUT produced by mtx
#  thus we sometimes get better changer results.
#
make_err_file() {
  ERRFILE=`mktemp @working_dir@/mtx.err.XXXXXXXXXX`
  if test x${ERRFILE} = x; then
     ERRFILE="@working_dir@/mtx.err.$$"
     if test -f ${ERRFILE}; then
	echo "ERROR: Temp file security problem on: ${ERRFILE}"
	exit 1
     fi
  fi
}


#
# The purpose of this function to wait a maximum
#   time for the drive. It will
#   return as soon as the drive is ready, or after
#   waiting a maximum of 300 seconds.
# Note, this is very system dependent, so if you are
#   not running on Linux, you will probably need to
#   re-write it, or at least change the grep target.
#   We've attempted to get the appropriate OS grep targets
#   in the code at the top of this script.
#
wait_for_drive() {
  i=0
  while [ $i -le 300 ]; do  # Wait max 300 seconds
    if mt -f $1 status 2>&1 | grep "${ready}" >/dev/null 2>&1; then
      break
    fi
    debug "Device $1 - not ready, retrying..."
    sleep 1
    i=`expr $i + 1`
  done
}

# check parameter count on commandline
#
check_parm_count() {
    pCount=$1
    pCountNeed=$2
    if test $pCount -lt $pCountNeed; then
	echo "ERROR: usage: mtx-changer ctl-device command [slot archive-device drive-index]"
	echo "	Insufficient number of arguments given."
	if test $pCount -lt 2; then
	    echo "  Mimimum usage is first two arguments ..."
	else
	    echo "  Command expected $pCountNeed arguments"
	fi
	exit 1
    fi
}

# Check for special cases where only 2 arguments are needed,
#  all others are a minimum of 5
#
case $2 in
    list|listall)
	check_parm_count $# 2
	;;
    slots)
	check_parm_count $# 2
	;;
    transfer)
	check_parm_count $# 4
	;;
    *)
	check_parm_count $# 5
	;;
esac


# Setup arguments
ctl=$1
cmd="$2"
slot=$3
device=$4
drive=$5

debug "Parms: $ctl $cmd $slot $device $drive"

case $cmd in
   unload)
      debug "Doing mtx -f $ctl unload $slot $drive"

      if test ${offline} -eq 1 ; then
        mt -f $device offline
      fi
      if test ${offline_sleep} -ne 0 ; then
        sleep ${offline_sleep}
      fi
      make_err_file
      ${MTX} -f $ctl unload $slot $drive 2>${ERRFILE}
      rtn=$?
      cat ${ERRFILE}
      rm -f ${ERRFILE} >/dev/null 2>&1
      exit $rtn
      ;;

   load)
      debug "Doing mtx -f $ctl load $slot $drive"
      make_err_file
      ${MTX} -f $ctl load $slot $drive 2>${ERRFILE}
      rtn=$?
      if test ${load_sleep} -ne 0 ; then
        sleep ${load_sleep}
      fi
      wait_for_drive $device
      cat ${ERRFILE}
      rm -f ${ERRFILE} >/dev/null 2>&1
      exit $rtn
      ;;

   list)
      debug "Doing mtx -f $ctl -- to list volumes"
      make_temp_file
      if test ${inventory} -ne 0 ; then
        ${MTX} -f $ctl inventory
      fi
      ${MTX} -f $ctl status >${TMPFILE}
      rtn=$?
      if test ${vxa_packetloader} -ne 0 ; then
        cat ${TMPFILE} | grep " *Storage Element [0-9]*:.*Full" | sed "s/ Storage Element //" | sed "s/Full :VolumeTag=//"
      else
	cat ${TMPFILE} | grep " Storage Element [0-9]*:.*Full" | awk "{print \$3 \$4}" | sed "s/Full *\(:VolumeTag=\)*//"
      fi
      cat ${TMPFILE} | grep "^Data Transfer Element [0-9]*:Full (Storage Element [0-9]" | awk '{printf "%s:%s\n",$7,$10}'
      rm -f ${TMPFILE} >/dev/null 2>&1
      exit $rtn
      ;;

   listall)
#  Drive content:	  D:Drive num:F:Slot loaded:Volume Name
#  D:0:F:2:vol2        or D:Drive num:E
#  D:1:F:42:vol42
#  D:3:E
#
#  Slot content:
#  S:1:F:vol1		  S:Slot num:F:Volume Name
#  S:2:E	       or S:Slot num:E
#  S:3:F:vol4
#
#  Import/Export tray slots:
#  I:10:F:vol10 	  I:Slot num:F:Volume Name
#  I:11:E	       or I:Slot num:E
#  I:12:F:vol40

      debug "Doing mtx -f $ctl -- to list all"
      make_temp_file
      if test ${inventory} -ne 0 ; then
        ${MTX} -f $ctl inventory
      fi
      ${MTX} -f $ctl status >${TMPFILE}
      rtn=$?
      # can be converted to awk+sed+cut, see below
      perl -ne '
/Data Transfer Element (\d+):Empty/ && print "D:$1:E\n";
/Data Transfer Element (\d+):Full \(Storage Element (\d+) Loaded\)(:VolumeTag =\s*(.+))?/ && print "D:$1:F:$2:$4\n";
/Storage Element (\d+):Empty/ && print "S:$1:E\n";
/Storage Element (\d+):Full( :VolumeTag=(.+))?/ && print "S:$1:F:$3\n";
/Storage Element (\d+) IMPORT.EXPORT:Empty/ && print "I:$1:E\n";
/Storage Element (\d+) IMPORT.EXPORT:Full( :VolumeTag=(.+))?/ && print "I:$1:F:$3\n";' ${TMPFILE}
      # If perl isn't installed, you can use by those commands
#cat ${TMPFILE} | grep "Data Transfer Element" | awk "{print \"D:\"\$4 \$7 \$9 \$10}" | sed "s/=/:/" | sed "s/Full/F:/" | sed "s/Empty/E/"
#cat ${TMPFILE} | grep -v "Data Transfer Element" | grep "Storage Element" | grep -v "IMPORT/EXPORT" | awk "{print \"S:\"\$3 \$4 \$5}" | sed "s/IMPORT\/EXPORT//" | sed "s/Full *:VolumeTag=/F:/" | sed "s/Empty/E/"
#cat ${TMPFILE} | grep -v "Data Transfer Element" | grep "Storage Element" | grep "IMPORT/EXPORT" | awk "{print \"I:\"\$3 \$4 \$5}" | sed "s/IMPORT\/EXPORT//" | sed "s/Full *:VolumeTag=/F:/" | sed "s/Empty/E/"

      rm -f ${TMPFILE} >/dev/null 2>&1
      exit $rtn
      ;;

   transfer)
      slotdest=$device
      debug "Doing transfer from $slot to $slotdest"
      ${MTX} -f $ctl transfer $slot $slotdest
      rtn=$?
      exit $rtn
      ;;

   loaded)
      debug "Doing mtx -f $ctl $drive -- to find what is loaded"
      make_temp_file
      ${MTX} -f $ctl status >${TMPFILE}
      rtn=$?
      cat ${TMPFILE} | grep "^Data Transfer Element $drive:Full" | awk "{print \$7}"
      cat ${TMPFILE} | grep "^Data Transfer Element $drive:Empty" | awk "{print 0}"
      rm -f ${TMPFILE} >/dev/null 2>&1
      exit $rtn
      ;;

   slots)
      debug "Doing mtx -f $ctl -- to get count of slots"
      ${MTX} -f $ctl status | grep " *Storage Changer" | awk "{print \$5}"
      ;;
esac
